Louver modules are commonly known in the art and are used for a variety of applications such as for cooling towers, closed circuit coolers and evaporative condensers. One example of a commercial application for louver modules is employed in a conventional heat exchanger 100 as described in U.S. Pat. No. 6,923,250 and as illustrated in FIGS. 1-6. The conventional heat exchanger 100 includes a cabinet 102 that houses an exhaust fan 104, a manifold 106, a direct heat exchanger medium 108 and a plurality of conventional louver modules 110. As is commonly known in the art, the manifold 106 supplies water via spray nozzles 112 in a spray form to the direct heat exchanger medium 108 while the exhaust fan draws air represented by the solid single-line arrows from outside the cabinet 102 though the louver modules 110. As the water flows downwardly along the direct heat exchanger medium 108 and as air is drawn upwardly by the exhaust fan 104 through the direct heat exchanger medium 108, heat is effectively exchanged between the flowing water and the moving air. After heat has been exchanged, the water drips into and accumulates in a water basin 113.
As shown in FIGS. 2-5, each louver module 110 forms a plurality of air passageways 116 having trapezoidal cross-sectional configurations defined between respective louver walls 118. As a shown in FIG. 4, each air passageway 116 is bent at an approximate central location X in a sideways V-shape as viewed in plan view as each air passageway 116 extends from outside and into the cabinet 102. Although a bent air passageway 116 introduces a slight pressure drop of the air pressure as air enters into the cabinet, there are advantages of having bent air passageways.
With reference to FIG. 4, sunlight represented by the dashed arrow SL cannot readily enter into the cabinet 102 as a result of bent air passageways. Significantly reducing the amount of sunlight that enters into the cabinet through the louver modules 110 retards the growth of algae, mold or microorganisms in the water basin 113. It is commonly known in the art of heat exchangers that growth of algae, mold or microorganisms is promoted by sunlight and prevention of such growth reduces maintenance cost of the heat exchanger. Furthermore, as shown in FIG. 5, the air passageways 116 are angled downwardly relative from the outside of the cabinet 102 to the inside of the cabinet 102 at an angle Z of approximately 100 in a width-wise direction extending parallel to a horizontal axis H. This downwardly orientation of the air passageways 116 into the cabinet 102 prevents or reduces an amount of water splashing out of the heat exchanger 100 and also allows any water that may have accumulated in the air passageway or on the backside of the louver module to drain back into the water basin.
However, there is a drawback in providing a louver module 110 having bent air passageways 116 as described above. Although bent air passageways 116 are effective in retarding the growth of algae, mold and microorganisms, the heat exchanger efficiency of such heat exchanger is reduced. As shown in FIG. 6, it has been observed in a laboratory setting that as air represented by the solid-line arrows enters into the cabinet 102 through the louver modules 110, the bent air passageways 116 cause the air above the water basin 113 and below the direct heat exchanger medium 108 to swirl (represented by solid-line arcuate arrows) in somewhat of a circular fashion. Such swirling of air inside the cabinet 102 above the water basin 113 and below the direct heat exchanger medium 108 causes poor air distribution within the cabinet and a reduction in air pressure in at least some areas below the direct heat exchanger medium 108 negatively impacting the flow of air over the water flowing downwardly on the direct heat exchanger medium 108 at these areas. It is desirable to maintain uniform air and water distribution across the heat exchanger medium to ensure optimal thermal efficiency.
Furthermore, a shown in FIGS. 4 and 6, the air enters into the cabinet 102 at an air entry angle Y relative to the horizontal axis H. It has been observed in the laboratory that the air entry angle Y at which the air enters the cabinet 102 contributes to this swirling effect.
It would be advantageous to provide a louver module having a plurality of air passageways that inhibit sunlight from entering into the water basin of a heat exchanger cabinet and simultaneously direct air to enter into the cabinet generally parallel to the width-wise direction of the louver module. It would be beneficial to provide a louver module having a plurality of air passageways that inhibits or eliminates air swirl inside the cabinet. The present invention provides this advantage and this benefit.